Reservoir pen



April 12, 1932. T. KOVACS 1,853,731

RESERVOIR PEN' Filed Aug. '7; -1930 Arty.

l 2o1 Accordmg VPatented apr. 12.1932;

-giNirED srA'rl-:s APAfri?.NTL--ori-fici;

'rnnonon xovAcs, or BEBLINKGERMANY. AssIGNon 'ro man man @Umgang WAGNER.

OF GERMANY Application med/August 7, 1980.`Seria1 No j My I 10periodically closes the air inlet openin of the nib.' When the thereservoir pen is diaphragm of ink which forms on use air `rises in .theair passage a1r. and abody of 15- at increasing velocity. As thevelocity of the air increases, the flow of ink toward the nib increasesalso, and the 'inlet'opening of the, nib is a ain closed by the ink.`This cycle is repeate periodicall l'o m surging is reduce invention theperiodical 'to a minnnum. I have Afound thatthe restriction of the airassage P 'must .be such as to make up for the increase ofjow intensity.which results from 'the increasing headby' the lresistance ofthe ink` crising in the airjpas'sage, 'which resistance increases as thecross-sectional area of ,thg pasf -sage decreases.,l f l' Y M Thelargpstcross-sectionalarea of the air l0 passage is 1n the vicinity ofthe airinlet openmg o the nib. The section'atthis point 1s so large thatthe surging which 1s still present notwithstanding the restriction ofthe airpas- 'sa will not close the air inlet opening.

e airpassage must not be restricted too much .at its upper end asitmight become clogged, andstherefore the' restriction zonly extends toabout the level of the end of the nib, and the air passage is abruptlyextended atthis point. A l j .In-the drawings aixedto-thisspecification,andjformingpart thereof the lower endbf a reservoir en embodyinginyinvention is -illustrated iagrammatically by wayV of examp ble.

invention relates to reservoirpens. 1t' is an obj ect' of my inventionto prevent sur .sectional area of which is l the inlet KK opening of thenib is broken by the make-up with two capillary giooves nasse, una inGermany August-19, 1929'.

In' the drawings l the feed bar of a reservoir pen on the line I\V'I inFig. 2, drawn to/a magnified scale,

Figs. '2, 3 and 4 are cross sections of the feed lbar and the nib onthecorresponding o lines in Fig. 1, i

Fig.- 5 is an end elevation of the feed bar ,Y viewed yinthedirec'tionfof the arrow V inf.. v Fig-1,- -t- Fig. 6 is an elevationof the feed bar viewed from the left-inxFig. 41,- and S Fig. 7 is alongitudinal section of the feed bar Jtaken on the line VII-VII in Fig.3.

' Referring now to the drawings, A is thev neck of the reservoir penB-islthe feed bar, C is the nib, and D is its air` inlet opening. E.y isthe passagefn the feed bar which is'p'ovided F--F at its base. Anynumber of ooves'may be rovided in- .stead of two.^ `T` e cross-sectiona'area ofthe assageE is largest at'the level of the`air fromthis point itis gradually restricted to a` point which is about at the level of theupper end ffthe nib C. o Preferably the depth of the airpassagesE isvaried-by a parabolic law. For' the sake of convenience, the bottom oftle passage E has been shown straight and may be madestraightinpractice. The fled bar is stepped at H near 73 its" upper endv so t tthecross-sectionalarea of the air passage E is `abruptly increased tolform an'ante chamber N offthe reservoir K.

The feed barB has a'substailtially cylinlnlet opening D and dricalcentral portion 1, with which it .fits the 80- boreof 4the neck A. Theseat for the nib C is also formed by this central portion, the` nibbeing tcaught between the central portion and the inner wall of the neckA. The rear faceofLV the central portion, i. e., the-face whichis op 35positethe `seat for the nib' C, is' lstepped at 2 and from this point toits lower ,end 3 the configuration of the feed barv at its backresembles the letter S, as shown in Fig. 1. The-back itc self isstraight in transverse directiomas will l0 Fig. 1 is a section oftheneck, the'nib and l p 4 only the central rib 16.

appear from Figs 2 and 3. The front face of the feed bar from its lowerend 3 to the point 4 at the lower end of the step H is parallel to thenib C and from the point 4 it is shaped 5 like the letter Z, 4having akink 6 at the upper end of the step H, and another kink at 7. Theportion from the kink 7 to the upper end 5 of the feed bar may beparallel to the step H. The passage E is straight from its intersec- 10tion 8 with the step H to a point 9 which is a short distancbelow theupper end of the ai;`

. inlet opening D, and slightly inclined toward the back of the feedbar. From the point 9 Yto a point 33 above the lower end 3 of the feedbar it is curved. As mentioned, its bottom, supposing that its width isconstant, should be curved on a parabola, but for practicalconsiderations it is preferred to make it straight from 8 to 9.

out the length' of the eed bar from a point 55 just below its upper end5 to a point 33. just above its lower end 3. They are`kinked from 55 to77 in parallel to the step 7, 5, then extend in parallel to the straightportion 6,

7 from the point 77 and beyond 6, 7 to a point 99 at the level of thepoint 9, and from here in a curve reach the point 33. The lower portionof the feed bar isrecessedat both sides 39 of the passage E from pointslO'which are situated about at the level pfpoint 2 to points 11 whichare about at the level o point 9. The two recesses 12 and 13 appear inFigs. 2 'and 3 which also show the two walls 14 and 3 5 l5 at the sidesof the passages E and F, F and the central rib 16 between the passagesF, F. The sectionfin Fig. 4 extends throu hthe substantially solidcentral portion 1 o the bar B and does not show the recesses 12 Assumethat the reservoir K and the antechamber N are iilled with a writingliquid, which may benormal writingink, india ink or thelike, and thatthe ink at the lower en of the air passage E is at the level M. The

remaining portion of the passage is illed l with a continuous body ofair which at its ulpper end G has penetrated into the anteamber N andat' the next instant will rise as a. very small bubble. Surging occursupon .the detaching'of the bubble, the ink penetrating into the passageE as far as the level J, -and rising as far as the level L at the lowerend of the passage. 4As mentioned, the level L must not rise so far asto close the air.- inlet opening D, the cross-sectional area ofthepassage at .this point being suitably proportioned. 1. is the vesicalhead of the @011mm of liquid which is suspended from the main body of,L0 the liquid at J' and extends through the oo ves F to the end ofthenib C. The head p and the resistance of the/,meniscus at J determine theintensity of' the flow. As the ink is consumed upon writing, the level Jrises l5 and 1|. increases. At the same time, however,

lThe capillary passages F extend throughv and 13 but the surface of theink is reduced on account ofthe gradual restriction 'of the passage sothat the resistance against upward movement f the liquid due to itssurfacetension, is in-n creased. With an air passage E designed asdescribed in which the cross-sectionallarea of the passage is restrictedas a fuiction ofthe head i1. the oW of the liquid becomes constant or issubjected to small variations only, so that surging to any appreciablelextent is prel vented.

Variations of the cross-sectional area of the air passage E may beeffected by varying its" depth, as shown, by varying its width, or byvarying both factors. However, I may also design the air passage withconstant crosssectional area and so arrange V.the nib c that itpenetrates deeper into the passage at its upper end than atits lower enI wish it to be understood that I do not desire to be limited to theexact details of i construction shown and described for ob;

vious modifications will occur to a person',

skilled in the art. l f.

In the claims aixed to this specification no selection of any particularmodification of theinvention lis intended to the exclusion of othermodiiications thereofV and the right to subsequently make claim to anymodification not covered by these claims is expressly re` o'nnected withsaid reservoir, the cross-sec-v tional area of which passage isgradually `reduced from "said nib toward said reservoir -at such a ratethat at any position of the surface of the ink in said passages thecapillary forces at the edge of said surface exceed the iisv suctionacting on the surface for a constant amount.

3. A reservoir pen comprising a reservoir for a writin li uid, a nibyhaving an. air inlet opening, an a eed bar extending from saidreservoir to `said nib and having an air-passage and capillary groovesconnected with said reservoir, the cross-sectionall area of 'whichpassage is gradually reduced from said nib toward said reservoir, and isso lar at the level of' said air inlet opening that t e liquid in saidpassage will not close said air inlet lopening when surging of theliquid occurs. k, 4. A reservoir pen comprising a reservoir for awritingliquid, a nib, and afeed bar extending from said reservoir tosaid nib and having an air passage and capillary grooves yconnected withsaid reservoir, the cross-see- -tionai area of yvhh passage 1s graduallyre- .duced from sald nib toward said reservoir at such a rate that atany position of thesurface of the ink in said passages the capillaryforces at the edge of said surface exceed the suction acting on thesurface for a constant amount, with an abrupt increase of`cross-sectional area near the upper end of said nib.A

1n testimony whereof I aix my signature.

THEODOR IKOVGS.

